so this extraordinary moment in history, using the former joseph ratzinger who will be within hours be pope emeritus, getting into the car for this short ride to the helipad leaving the grounds of vatican city for the last time as the head of the roman catholic church. and liz lev, as our historian, give us some historical perspective and what you're seeing as you see this, as someone who has been so close to the vatican and lived ed id ino longe? >> i'm looking at this courtyard, which has had so many different events take place